Two sets suffices for the tutorial. A smaller one can be made with one set, and larger ones with four sets or more
Care is required in construction of the ribbon to make sure it has no double diamonds or double squares, but it is easy to make if care is taken, and quick to make once you are practised at it.
See also solid pillow cube: http://www.youtube.com/watch?v=hPrbYUyrSMM